In the given sentences, we need to choose the correct personal pronouns to complete the sentences appropriately.
1. "5 Ting and I is my friend." - The correct pronoun to use here is "I." The sentence should be: "5 Ting and I are my friend."
2. "… is fat." - The correct pronoun to use here is "she." The sentence should be: "She is fat."
3. "… is a red dress." - The correct pronoun to use here is "it." The sentence should be: "It is a red dress."
By using the appropriate personal pronouns in each sentence, we ensure that the sentences are grammatically correct and convey the intended meaning clearly. Personal pronouns replace nouns to make sentences shorter and less repetitive while maintaining clarity in communication.